Fuel economizer



Patented Apr. 14, 1936 o I I UNITED STATES PATENT OFFICE FUEL ECONOMIZER Gene J. Judd and Charles A. Morgan Indianapolis, Ind.

Application January 24, 1935, Serial No. 3,350

6 Claims. (01. 122-379) v This invention relates to apparatus for utilizto be considered as being limited to the primary ing the heat of flue gases escaping froma furnace. source of flue gases as coming from a hot air A primary object of the invention is to provide furnace. I a structure through which flue gases may travel Flue gases are conducted from the economizer and be transferred to some heating medium such l0 through the pipe 15 and thence on into the '5;

as water capable of .being used in an auxiliary stack (not shown). It is important to have the heat transfer system. A further primary object smoke pipes 13 and 15 entering and leaving, of the invention is to provide such apparatus in respectively, the economizer I0 at the same elea very simple, durable, and efficient form which vation as will be discussed more fully hereinwill provide for the greatest transfer of heat from below. 10

such gases without setting up a cooling effect The economizer unit itself will now' be deupon non-flow of the heated gases through the s d- We pr v d a b of metal. Cast device. iron being suitable. The base is preferably made A still further primary object of the invention to be narrower in width than its length and 15 is to provide means in the heat economizingaphas a number of transversely disposed bars ll 15 paratus which would permit an expansion of the resting thereon. Each of these bars I1 has a heated flue gases within the device to permit them foot l8, Fig. 6, at each end, downturned to rest to rise above the ordinary straight line passage on the base 16 so as to leave an opening beof the gases between the inlet and outlet gas tween the base a d. the bar. 1

conductors. We place a number of tube sections 19 in 20 A still further important object of the invenparallel relation on these bars I! to extend lontion is to provide very simple and efficient means gitudinally of the base 16. Each section is spaced for cleaning the exterior surfaces of the coils from the adjacen Section, and is C p of or pipes containing the Water being heated by a series of tubes 20 spaced one from the other.

the flue gases. These and other objects and ad- It is part cu a y desired that a of t s 25 vantages of the invention including the new and tubes Within each Section have flat surfaces 6X- novel assembly of the various elements as detending throughout their vertical lengths rather fined by the claims, will become apparent to than round surfaces. In the form herein those skilled in the art and reference is made shown, these tubes 20 are rectangular in shape to the accompanying drawings in describing one thus presenting four exterior flat faces. The 30 particular form of our invention as now best sections are interconnected one with the other known to us. by nipples 2| across their lower ends adjacent Referring to the drawings, Fig. 1 is a side eleone end .of the base l6, suc end being the left vation in a more or less diagrammatic form of an hand end as viewed in Fig. 1 or that end toward installation embodying our invention. the flue gas intake of the economizer. The sec- 35 Fig. 2, an end elevation of the economizer tions are similarly interconnected by nipples 22 unit with the end wall broken away, at their upper and opposite ends as indicated in Fig. 3, a detail in horizontal section on the Fig.2. line 3-3 in Fig. 1, We provide a housing which rests on the base 40 Fig, 4, horizontal transverse section on the I6 to completely 61101058 the tubular sections is 4 line 4--4 in Fig. 1; assembled as above indicated. This housing is Fig. 5, a detail in side elevation of the scrapa box-like structure spaced from the sections ing mechanism, somewhat and securely held in place by the Fig. 6, a detail in horizontal transverse section bolts 23 extending through ears 24 .on the housof the water tube support, and ing and through the base It. In the form here- 5 Fig. '7, an end view of the scraper. in shown, we have provided the housing with 9. Like characters of reference indicate like parts double wall on its two sides and top so as to throughout the several views in the drawings. receive water therein to form a water jacket to Referring to Fig. 1, the economizer unit, genfurther absorb heat from flue gases. The end erally designated by the numeral 10, is mounted Walls are preferably left single on account of 50 upon a supporting base or frame H so as to have being easier to assemble in that condition; the inlet collar I 2 at the proper elevation above As above indicated the flue gas intake collar 12 the floor to receive the smoke pipe 13 extending is located on the end wall of the economizer tofrom the heating furnace I l, herein shown as a ward the base 16 at that end where the sections hot air furnace, although the invention is not 19 are interconnected by the nipples 2| on their 55 pressure is removed from the pedal 42.

lower sides. The outlet pipe l5 preferably leaves the housing from a side but adjacent the opposite end as indicated in Fig. 4, the pipe I5 being received by the collar 25. Both the collars l2 and 25 are at the same elevation above the base I6. Furthermore the collars are carried by the housing in an extended position so as to form as indicated in Fig. 2 a chamber 26 between the collars and the sections l9 to give ample room for flue gas travel without having the sections l9 interfering therewith.

It is necessary, in order to secure the greatest exchange of heat from the flue gases entering the economizer II] to keep the exterior walls of the tubes 20 in the sections l9 clean and free of coal soot. To this end, we provide a scraping mechanism which will now be described. We form a framework 2'! which will just fit within the housing on the outside of the sections I!) so that it may be raised and lowered thereabout. We then fix to this frame 21, channel bars 28 to extend longitudinally of the sections l9 to have the upturned legs thereof in frictional contact with the opposing walls of the tubes within those sections. There is also a channel bar 28 on the outermost sides of the outer sections [9 to travel between those outer sections and the wall of the housing. We also mount a plurality of channel bars 29 to extend transversely across the bars 28, one such bar 29 being between each of the opposing faces of the tubes in the sections and also a bar on each extreme outer end of the sections between them and the end walls of the housing.

These channel bars 28 and 29 are preferably formed to have their legs extending angularly outwardly against the respective tubular walls so as to exert a shearing action therealong tending to cut and shave off the accumulation of scale and soot along the tubular walls. By reason of the fact that the tubular walls present flat faces, it is to be noted that all of the area of those faces may be readily scraped by the projecting edges of the channel bars 28 and 29 as the frame 21 may be raised within the housing.

In order to reciprocate the frame 21 to effect the scraping of the tubes, we attach a shaft 30, here shown as centrally of the frame 2! and cause it to extend downwardly through the floor l6 through a stufiing box 3| so that the shaft 30 may be raised and lowered therethrough and a gas tight fit maintained therearound. The lower end of the shaft 30 is fitted with a grooved wheel 32 which rides over inwardly turned flanges 33 and 34 of the respective T irons 35 and 36 which are fitted to the under side of the base or floor IS on the bracket 31 to hang downwardly therefrom.

The axle 38 about which the wheel 32 is mounted on the shaft 30 extends outwardly on both sides of the mounting bracket 39. One end of the extending axle 38 enters a slot 40 in the end of a lever 4| which is rockably mounted on the supporting frame II to have a foot pedal 42 extending therefrom. By pushing downwardly on the pedal 42, the shaft 30 may be raised so as to lift the scraper frame 2! to cause the channel members 28 and 29 to scrape the tubes as the members are carried upwardly thereby. The weight of these members and their frame is sufficient to cause them to drop downwardly when In order to prevent damage by dropping of the channels under their own weight, we provide a counter-balance 43, Fig. 2, which is attached to the end of a cable 44 passing upwardly over a pulley 45 secured to the floor l6 and thence downwardly to an end of the axle 38.

In the form herein shown, where the sections !9 are designed to carry water to which the heat is to be transferred from the flue gases, we provide an inlet pipe 46 which enters the lower end of one of the sections H3 at the inlet end and base thereof. An outlet pipe 41 leads from the top of one of the sections l9 and is carried upwardly. The pipes 46 and 41 are suitably interconnected with a heat radiating member 48, here shown as a radiator of the common and well known type, so that as the water in the sections l9 may become heated, a circulation of the water will be had through the radiator 48.

In operation, whenever there is a fire in the furnace I 4, flue gases will escape from that furnace through the pipe 13 and enter within the housing of the economizer I 0 to pass about and around the various tubes of the sections IS. The gases may escape through the outlet pipe l5 which, as above indicated, is maintained at the same level as that of the intake pipe l3. By reason of the arrangement of these pipes l3 and I5, the flue gases immediately upon entering within the collar l2 may expand and rise upwardly within the housing of the economizer and heat the upper portion of the surface without any direct draft through that upper part. The draft is maintained across the under ends of the sections l9 so that the difficulty sometimes encountered heretofore in economizers is eliminated by preventing the cooling off of the tubes in the sections I!) by passage of air through the device which has not been heated or which passes so rapidly as not to give up a suflicient amount of the heat to heat the water within the tubes.

In referring again to the scraping mechanism, it is to be noted that each of the channel bars 28 are cut through between webs at the sides of the respective tube faces so that the soot and scale scraped oif may drop through the openings 49 and down onto the floor l6. Likewise the transverse channels 29 are cut through to leave openings 50 on the other sides of the tube faces to provide similar discharge openings. A cleanout door 5| is provided in one end of the economizer wall so that the door may be removed and the accumulation on the floor I6 scraped along under the bars I! to discharge into some suit- I able receptacle (not shown) over the lip 52.

While we have herein shown our invention in the best form as now known to us, it is obvious that structural changes may be made without departing from the spirit of the invention and we therefore do not desire to be limited to that precise form beyond the limitations as may be imposed by the following claims.

We claim:

1. In a flue gas heat transfer device, a plurality of vertically disposed interconnected heat receiving tubes having plane faces angularly disposed one to the other, a housing surrounding the tubes in spaced relation, a scraper unit comprising upturned scraping members extending between said tubes to have edges thereof in parallel relation to and in contact with said tube faces, and means for moving said members upwardly along said faces, said housing having flue gas intake and outlet openings removed one from the other and both at the same elevation near the base of said tubes.

2. In a flue gas heat transfer device, a plurality of vertically disposed interconnected heat receiving tubes having plane faces angularly disposed one to the other, a housing surrounding the tubes in spaced relation, a scraper unit comprising upturned scraping members extending between said tubes to have edges thereof in parallel relation to and in contact with said tube faces, and means for moving said members upwardly along said faces, said means comprising a shaft connected with said members and extending from the housing, and an operating lever interengaging said shaft.

3. For utilizing heat from flue gases escaping from a furnace, an economizer to be placed in the smoke-pipe of the furnace comprising, a base, a plurality of tubular sections, means for supporting and spacing the sections from the base in spaced apart parallel relation, said sections being interconnected across their lower and top ends, the tubes in each section being, formed to have vertically disposed plane faces, scraping members extending horizontally between the tubes to have scraping edges parallel to all of the tube faces, and means for moving said members along said tubes.

4. In an economizer, a plurality of vertically disposed tubes each having a plurality of plane faces, and a tube scraping unit comprising horizontally disposed members arranged to extend between and around the tubes parallel with said faces, each of said members having edges directed toward and in contact with respective tube faces, and each of said members being provided with openings therethrough adjacent each of said faces.

5. In an economizer, a plurality of vertically disposed tubes each having a plurality of plane faces, and a tube scraping unit comprising horizontally disposed members arranged to extend between and around the tubes parallel with said faces, each of said members having edges directed toward and in contact with respective tube faces, and each of said members being provided with openings therethrough adjacent each of said faces, a floor supporting said tubes in spaced relation therefrom, a vertical shaft connecting with said members and slidably passing through said floor, guide means maintaining said shaft in alignment, and an operating lever interconnected with said shaft.

6. In an economizer, a plurality of vertically disposed tubes each having a plurality of plane faces, and a tube scraping unit comprising horizontally disposed members arranged to extend between and around the tubes parallel with said faces, each of said members having edges directed toward and in contact with respective tube faces, and each of said members being provided with openings therethrough adjacent each of said faces, a floor supporting said tubes thereabove, and a housing surrounding the tubes forming, a box-like enclosure over said floor, said housing having flue gas inlet and outlet openings in removed walls thereof at the same elevation, and said tubes having an inlet pipe at their lower ends near said housing inlet opening and having an outlet pipe at their upper ends above said housing outlet opening.

GENE J. JUDD. CHARLES'A. MORGAN. 

